/Engine/Source/Runtime/Engine/Classes/Kismet/BlueprintPathsLibrary.h
Takes a fully pathed string and eliminates relative pathing (eg: annihilates ".." with the adjacent directory). Assumes all slashes have been converted to TEXT('/'). For example, takes the string: BaseDirectory/SomeDirectory/../SomeOtherDirectory/Filename.ext and converts it to: BaseDirectory/SomeOtherDirectory/Filename.ext
static bool CollapseRelativeDirectories ( const [FString](API\Runtime\Core\Containers\FString) & InPath, [FString](API\Runtime\Core\Containers\FString) & OutPath )